Molina-Hidalgo Francisco Javier, Medina-Puche Laura, Cañete-Gómez Carlos, Franco-Zorrilla José Manuel, López-Vidriero Irene, Solano Roberto, Caballero José Luis, Rodríguez-Franco Antonio, Blanco-Portales Rosario, Muñoz-Blanco Juan, Moyano Enriqueta
Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus Universitario de Rabanales y Campus de Excelencia Internacional Agroalimentario CEIA3, Universidad de Córdoba, 14071 Córdoba,Spain.
Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus Universitario de Rabanales y Campus de Excelencia Internacional Agroalimentario CEIA3, Universidad de Córdoba, 14071 Córdoba, Spain.
J Exp Bot. 2017 Jul 20;68(16):4529-4543. doi: 10.1093/jxb/erx257.
Only a few transcription factors have been described in the regulation of the strawberry (Fragaria x ananassa) fruit ripening process. Using a transcriptomic approach, we identified and functionally characterized FaDOF2, a DOF-type ripening-related transcription factor, which is hormonally regulated and specific to the receptacle, though high expression levels were also found in petals. The expression pattern of FaDOF2 correlated with eugenol content, a phenylpropanoid volatile, in both fruit receptacles and petals. When FaDOF2 expression was silenced in ripe strawberry receptacles, the expression of FaEOBII and FaEGS2, two key genes involved in eugenol production, were down-regulated. These fruits showed a concomitant decrease in eugenol content, which confirmed that FaDOF2 is a transcription factor that is involved in eugenol production in ripe fruit receptacles. By using the yeast two-hybrid system and bimolecular fluorescence complementation, we demonstrated that FaDOF2 interacts with FaEOBII, a previously reported regulator of eugenol production, which determines fine-tuning of the expression of key genes that are involved in eugenol production. These results provide evidence that FaDOF2 plays a subsidiary regulatory role with FaEOBII in the expression of genes encoding enzymes that control eugenol production. Taken together, our results provide new insights into the regulation of the volatile phenylpropanoid pathway in ripe strawberry receptacles.
在草莓（Fragaria x ananassa）果实成熟过程的调控中，仅有少数转录因子被描述。我们采用转录组学方法，鉴定并对FaDOF2进行了功能表征，FaDOF2是一种与成熟相关的DOF型转录因子，它受激素调控且特异性表达于花托，不过在花瓣中也发现其表达水平较高。FaDOF2的表达模式与果实花托和花瓣中丁香酚含量相关，丁香酚是一种苯丙烷类挥发性物质。当在成熟草莓花托中沉默FaDOF2的表达时，参与丁香酚合成的两个关键基因FaEOBII和FaEGS2的表达下调。这些果实的丁香酚含量也随之降低，这证实了FaDOF2是一种参与成熟果实花托中丁香酚合成的转录因子。通过酵母双杂交系统和双分子荧光互补实验，我们证明FaDOF2与先前报道的丁香酚合成调节因子FaEOBII相互作用，FaEOBII决定了参与丁香酚合成的关键基因表达的精细调控。这些结果表明，FaDOF2在控制丁香酚合成的酶编码基因的表达中与FaEOBII发挥辅助调节作用。综上所述，我们的研究结果为成熟草莓花托中挥发性苯丙烷类途径的调控提供了新的见解。
